Luminaire associate

ABSTRACT

A street lighting fixture and street lamp used in street lighting containing an accelerometer that is used to detect and characterize acceleration events on a street lighting fixture. The accelerometer readings may be combined with GPS technology to determine a relocation of the street lighting fixture.

BACKGROUND

Area and street lighting is one of the most important elements of a city's infrastructure. For such extensive lighting installations it is desirable to know the locations of individual luminaires for maintenance and other purposes involving planning and billing.

In many instances, maintenance and installation crews installing luminaires record the luminaire locations by their GPS coordinates. The GPS coordinates are often provided by GPS receivers carried by the installation crews as part of a crew's personal data assistant.

It occasionally happens that luminaires are moved and their new location coordinates are not recorded. This introduces bookkeeping errors and adds to the overhead of maintaining the city's lighting infrastructure. It may also result in incorrectly locating and therefore misinterpreting data provided by non-illumination functions that are associated with, and physically proximate to, the luminaire.

A need therefore exists for a luminaire associate that will also provide the luminaire's true position and the location of associated functions regardless of a relocation of the luminaire and its associate.

BRIEF DESCRIPTION OF ILLUSTRATIONS

FIG. 1 illustrates a lamp, luminaire associate, and a post.

FIG. 2 illustrates the luminaire associate sending a GPS message.

FIG. 3 illustrates a luminaire associate connected to an electric meter.

FIG. 4 illustrates severe wind battering the post supporting the luminaire associate.

FIG. 5 illustrates a vehicle impacting the post supporting the luminaire associate.

DETAILED DESCRIPTION

A luminaire installed in an area or street lighting system typically comprises a lamp, a luminaire associate that supplies power to the lamp at appropriate times and may perform other functions, and a post supporting the lamp and luminaire associate.

FIG. 1 illustrates the luminaire 100 comprising the lamp 110, the luminaire associate 120, and the supporting post 130. A GPS receiver is incorporated into the luminaire associate 120 and provides the true location of the luminaire associate 120 even if the luminaire associate 120 is relocated without recordation in the lighting utility's property database. An accelerometer is also incorporated into the luminaire associate. By this combination of the GPS receiver and the accelerometer, the luminaire associate 120 may also report accurate luminaire location and accelerations imparted to the post 130 on which the luminaire associate 120 is mounted.

An acceleration event is declared and reported if (1) the magnitude of the measured acceleration exceeds a prescribed threshold or (2) the spectrum of the measured acceleration has one or more spectral components that exceed one or more prescribed thresholds or (3) in the case of a multiple axis accelerometer, the previous case (1) or (2) wherein the case applies to a particular accelerometer axis.

The technical advantages to incorporating the combination of a GPS receiver and accelerometer into the luminaire associate 120 are manifold. Not only can the luminaire be accurately located following its relocation, any accelerometer data will be associated with the luminaire's accurate geographical location. The accelerometer data can be used for very many purposes including, but not limited to: (1) monitoring wind speeds or detection of winds exceeding certain limits and (2) detection of a vehicle impacting the luminaire support pole and (3) estimating traffic loading on adjacent streets through analysis of coupled vibration and (4) earthquake alerting and (5) tornado tracking.

Not illustrated but optionally included in the luminaire associate 120 is a communication device that allows the luminaire associate to communicate with at least one of the lighting utility's data centers, vehicles, maintenance worker crew, and data centers belonging to other infrastructures such as an electric power utility. Also not illustrated but optionally included in the luminaire associate 120 is a data recorder that records compressed or uncompressed accelerometer data and the time associated with the compressed or uncompressed accelerometer data. Such recorded data may be of value to the lighting utility for such actions as warranty claims, insurance actions, and maintenance and replacement or upgrade scheduling.

FIG. 2 illustrates the luminaire associate 120 sending a GPS message. The message may comprise three spatial location coordinates, ie x,y,z and time, t, and is denoted by GPS:(x,y,z,t). The GPS generated message may be sent to one or more of the lighting utility's data centers 220. The GPS generated message may be sent to a vehicle 230. The GPS generated message may also be sent to a maintenance worker crew 240.

Another embodiment is illustrated in FIG. 3. A utility meter, such as an electric meter 310, communicates its readings to the luminaire associate 120 by an electrical conductor 320 or by another communications means, not illustrated, such as an RF communications link, an optical communications link, or a sonic-based communication link. The meter's readings are recorded by the luminaire associate 120 or forwarded to an infrastructure's data center.

FIG. 4 illustrates the scenario 400 wherein the luminaire is subjected to extreme weather conditions such as an intense windstorm or a tornado. The accelerometer and GPS data may be used to report or store weather conditions within the city and such data may be communicated to one or more infrastructure data centers and to public safety officials. The data may also be of use for assessing damage to the lighting infrastructure and for processing insurance claims.

FIG. 5 illustrates the scenario 500 wherein a vehicle 510 or other massive moving object impacts the post 130. The impact will cause shock data to be noted and recorded or transmitted by the luminaire associate 120. The shock data may be accompanied by GPS produced data respecting time or position. Such data may be useful for summoning emergency response services and also useful for characterizing the magnitude and time of the incident for insurance and law enforcement personnel. 

1. A luminaire associate device for use with a luminaire in a street lighting system comprising: a luminaire associate powerline that delivers power to the luminaire associate; an energy storage device having a recharging circuitry operatively connected to the luminaire associate powerline; a power supply switch connected to the luminaire associate powerline and the energy storage device; a power distribution circuit connected to the power supply switch comprising a tilt switch or level monitor switch; a GPS receiver powered by the power supply switch; a multiple-axis accelerometer with analog-to-digital electronic converters powered from the power supply switch; and a computer connected to the power supply switch, the GPS receiver, and the multiple-axis accelerometer.
 2. The device of claim 1 further comprising at least one of the items in the group comprising an electronic gyroscope, a geomagnetic sensor, and an inclinometer.
 3. The device of claim 1 wherein at least two of the axes of the multiple-axis accelerometer are aligned in the luminaire associate so that the plane formed by the at least two of the axes is essentially parallel to the section of street below the luminaire associate device.
 4. The device of claim 1 further comprising a wireless message transceiver.
 5. The device of claim 1 further comprising a powerline communication (PLC) transmitter.
 6. The device of claim 5 where the PLC transmitter is a modified geometric harmonic modulation transmitter coupled to the luminaire powerline through a transient protection device.
 7. A method for determining an acceleration event of a luminaire associate mounted on a street light having a power source, a lamp pole, the street light, a GPS receiver and the luminaire associate comprising the steps of: sensing movement of the luminaire associate through a multiple-axis accelerometer within the street light, wherein the multiple-axis accelerometer has two axes forming a plane essentially parallel to a ground plane upon which the street light sits; recording a time and a date for sensed movement if the sensed movement exceeds a predetermined threshold; calculating a magnitude of a horizontal acceleration from data reported by the sensing through the multiple-axis accelerometer; determining a start of the acceleration event as the time and the date the magnitude of the horizontal acceleration if the magnitude exceeds the preset threshold; determining an end of the acceleration event as the time and the date the magnitude of the horizontal acceleration drops below the preset threshold; recording the horizontal acceleration data reported by each of the multiple-axis accelerometer's two axes at the time of the maximum value of the magnitude of the horizontal acceleration during the sensed movement.
 8. The method of claim 7 further comprising a step estimating the direction of the sensed movement to the luminaire associate by electronically calculating the angle of the sensed movement using the horizontal acceleration data recorded by each of the multiple-axis accelerometer's two axes at the time of the maximum value of the magnitude of the horizontal acceleration during the acceleration event.
 9. The method of claim 8 further comprising a step of transmitting the maximum value of the magnitude of the horizontal acceleration during the sensed movement and the direction of the sensed movement received by the luminaire associate.
 10. The method of claim 7 further comprising the steps of: fitting a template to approximate the magnitude of the horizontal acceleration during the sensed movement; and transmitting the defining elements of the template used to approximate the magnitude of the horizontal acceleration during the sensed movement.
 11. A method for detecting a luminaire associate relocation position from stored reference geographical position comprising the steps of: deriving an estimated geographical position for the luminaire associate from a GPS receiver contained within the luminaire associate; deriving an estimate of lateral displacement by electronically sampling and processing the multi-axis accelerometer data; combining the estimated geographical position and the estimated lateral displacement using a sensor fusion algorithm to form a single estimate of spatial translation; comparing the single estimate of spatial translation to a preset threshold of spatial translation; setting a luminaire associate relocation datum (LARD) if the single estimate of spatial translation exceeds the preset threshold of spatial translation.
 12. The method of claim 11 further comprising the step of broadcasting a signal that the LARD is set.
 13. The method of claim 12 further comprising the steps of: receiving a signal conveying a new stored reference geographical position for the luminaire associate; replacing the stored reference geographical position with the new stored reference geographical position; resetting the LARD; and ceasing broadcast of the signal that the LARD is set.
 14. A luminaire associate system comprising: a GPS receiver configured to report estimates of its geographical location, a multiple-axis accelerometer with analog-to-digital electronic converters providing estimates of its spatial translation, and a computer configured to fuse the GPS receiver reporting estimates and the multiple-axis accelerometer spatial translation estimates to detect the relocation of the luminaire associate from its stored reference geographical position.
 15. The system of claim 14 further comprising a transmitter for alerting maintenance crews to the apparent relocation of the luminaire associate.
 16. The system of claim 15 further comprising a receiver for receiving and storing a new stored reference geographical location.
 17. A luminaire associate system comprising a multiple-axis accelerometer with analog-to-digital electronic converters providing measurements of acceleration and a computer using the measurements of acceleration to characterize acceleration events. 